Questions[x2goclient](ubuntu)

I've been using X2Go for a while now to connect from Windows10 to remote Ubuntu server.

I've been using the X2Go Session Type "Connect to local desktop".

Everything was working last night. Today when I tried connecting the X2Go Client seems to connect. However, where the X2Go Client GUI normally displays the Ubuntu desktop, I get a black screen which temporarily shows X2Go logo/name.

There are quite a few pages related to X2Go Black Screen, but I couldn't find an answer to my problem. Here are a few I looked: x2go do not connect to active desktop session X2go Black Screen

While ssh'd into remote machine using putty simultaneously while X2Go client is connected and showing black screen, if I run x2golistdesktops from terminal, I see

theusername@:50
theusername@:1

I think the theusername@:50 is the X2Go connection. This concerns me b/c in info reported by X2Go client (see below) I see Info: Forwarding X11 connections to display 'localhost:0'.

I've tried restarted my local machine. I've also restarted the X2Go service on the remote Ubuntu machine. I was also able to connect to remote machine using putty with x11 forwarding and xming and get GUI (e.g. for emacs).

Here is info reported by X2Go:

Copyright (C) 2001, 2010 NoMachine.

See http://www.nomachine.com/ for more information.

Info: Proxy running in client mode with pid '7496'.

Session: Starting session at 'Fri Nov 13 11:28:10 2020'.

Info: Connecting to remote host 'localhost:58746'.

Info: Connection to remote proxy 'localhost:58746' established.

Info: Connection with remote proxy completed.

Warning: Unrecognized session type 'unix-kde-depth_32'. Assuming agent session.

Warning: Failed to read data from the X auth command.

Warning: Generated a fake cookie for X authentication.

Info: Using ADSL link parameters 512/24/1/0.

Info: Using cache parameters 4/4096KB/8192KB/8192KB.

Info: Using pack method '16m-jpeg-9' with session 'unix-kde-depth_32'.

Info: Using ZLIB data compression 1/1/32.

Info: Using ZLIB stream compression 4/4.

Info: No suitable cache file found.

Info: Forwarding X11 connections to display 'localhost:0'.

Session: Session started at 'Fri Nov 13 11:28:12 2020'.

Info: Established X server connection.

Info: Using shared memory parameters 0/0K.

When I connect with ubuntu gnome x2goclient to a x2goserver running ubuntu xfce, I am unable to resume a suspended session after a short time (+-5 minutes). I've run debug both on client and server to try and look for anything, but no error messages. The display on the client just freezes; the server seems to say it has been succesfully resumed. But the screen is unresponsive. If I terminate, and start a new session, everything works. But then 5 minutes later (after inactivity) the same problem occurs.

After a short period the client then says "no response received from remote server".

The issue does not occur on x2goclient running windows, there the session can be continued later.

Client debug (only relevant parts, cannot post everything here)

x2go-DEBUG-../src/sshmasterconnection.cpp:356> Creating new channel for reverse tunnel 57307
x2go-DEBUG-../src/sshmasterconnection.cpp:368> Connecting to "127.0.0.1":4713

x2go-DEBUG-../src/sshmasterconnection.cpp:392> New channel created
x2go-DEBUG-../src/onmainwindow.cpp:6618> Proxy wrote on stderr: "Warning: No data received from remote proxy within 30 seconds.\n"

Server info

Sep  3 06:59:38 lnz1-inno /usr/bin/x2goumount-session[1567193]: x2goumount-session has been called with options: j.oosterhuis-50-1599113954_stDXFCE_dp24
Sep  3 06:59:38 lnz1-inno /usr/bin/x2goumount-session[1567193]: SSHFS share already unmounted, taking care of further clean-up (C-j.oosterhuis-50-1599113954_stDXFCE_dp24)
Sep  3 06:59:38 lnz1-inno /usr/bin/x2gofeature: x2gofeature called with options: X2GO_FMBINDINGS
Sep  3 06:59:38 lnz1-inno /usr/share/x2go/x2gofeature.d/x2goserver-extensions.features: x2goserver-extensions.features called with options: X2GO_FMBINDINGS
Sep  3 06:59:38 lnz1-inno /usr/share/x2go/x2gofeature.d/x2goserver.features: x2goserver.features called with options: X2GO_FMBINDINGS
Sep  3 06:59:38 lnz1-inno /usr/share/x2go/x2gofeature.d/x2goserver-fmbindings.features: x2goserver-fmbindings.features called with options: X2GO_FMBINDINGS
Sep  3 07:00:12 lnz1-inno /usr/bin/x2goresume-session: x2goresume-session called with options: j.oosterhuis-50-1599113954_stDXFCE_dp24 800x600 adsl 16m-jpeg-9 us pc105/us 0 both no
Sep  3 07:00:12 lnz1-inno /usr/bin/x2gofeature: x2gofeature called with options: X2GO_RUN_EXTENSIONS
Sep  3 07:00:12 lnz1-inno /usr/share/x2go/x2gofeature.d/x2goserver-extensions.features: x2goserver-extensions.features called with options: X2GO_RUN_EXTENSIONS
Sep  3 07:00:12 lnz1-inno /usr/bin/x2goserver-run-extensions: x2goserver-run-extensions called with options: j.oosterhuis-50-1599113954_stDXFCE_dp24 pre-resume
Sep  3 07:00:13 lnz1-inno /usr/bin/x2goresume-session: client 192.168.23.106 has successfully resumed session with ID j.oosterhuis-50-1599113954_stDXFCE_dp24
Sep  3 07:00:13 lnz1-inno /usr/bin/x2gofeature: x2gofeature called with options: X2GO_DESKTOPSHARING
Sep  3 07:00:13 lnz1-inno /usr/share/x2go/x2gofeature.d/x2goserver-extensions.features: x2goserver-extensions.features called with options: X2GO_DESKTOPSHARING
Sep  3 07:00:13 lnz1-inno /usr/share/x2go/x2gofeature.d/x2goserver.features: x2goserver.features called with options: X2GO_DESKTOPSHARING
Sep  3 07:00:13 lnz1-inno /usr/share/x2go/x2gofeature.d/x2goserver-fmbindings.features: x2goserver-fmbindings.features called with options: X2GO_DESKTOPSHARING
Sep  3 07:00:13 lnz1-inno /usr/share/x2go/x2gofeature.d/x2goserver-printing.features: x2goserver-printing.features called with options: X2GO_DESKTOPSHARING
Sep  3 07:00:13 lnz1-inno /usr/share/x2go/x2gofeature.d/x2goserver-x2goagent.features: x2goserver-x2goagent.features called with options: X2GO_DESKTOPSHARING
Sep  3 07:00:13 lnz1-inno /usr/share/x2go/x2gofeature.d/x2goserver-xsession.features: x2goserver-xsession.features called with options: X2GO_DESKTOPSHARING
Sep  3 07:00:13 lnz1-inno /usr/bin/x2gofeature: x2gofeature called with options: X2GO_RUN_EXTENSIONS
Sep  3 07:00:13 lnz1-inno /usr/share/x2go/x2gofeature.d/x2goserver-extensions.features: x2goserver-extensions.features called with options: X2GO_RUN_EXTENSIONS
Sep  3 07:00:13 lnz1-inno /usr/bin/x2goserver-run-extensions: x2goserver-run-extensions called with options: j.oosterhuis-50-1599113954_stDXFCE_dp24 post-resume
Sep  3 07:00:15 lnz1-inno /usr/bin/x2gomountdirs[1568154]: x2gomountdirs has been called with options: dir j.oosterhuis-50-1599113954_stDXFCE_dp24 jacco /home/j.oosterhuis/.x2go/ssh/key.KozDcL /home/jacco/.x2go/S-j.oosterhuis-50-1599113954_stDXFCE_dp24/spool__PRINT_SPOOL___REVERSESSH_PORT__57308
Sep  3 07:00:16 lnz1-inno /usr/bin/x2gomountdirs[1568154]: successfully mounted [email protected]:57308/home/jacco/.x2go/S-j.oosterhuis-50-1599113954_stDXFCE_dp24/spool to /tmp/.x2go-j.oosterhuis/spool/C-j.oosterhuis-50-1599113954_stDXFCE_dp24

Which seems to say "succesfully mounted".

I use x2go (latest version installed from x2go ppa) to connect to another ubuntu 18.04 machine.

x2go has some shortcuts documented: https://wiki.x2go.org/doku.php/doc:usage:x2goclient

I'm specifically interested in

Ctrl + Alt + G: toggle autograb feature (pass all key to the x2go session when it is active; this helps with window cycling using Alt+Tab)

However, such shortcut seems to not work. Indeed, when I set the Display to Use whole display, the keyboard shortcuts are "grabbed" (that is, I can change the active window by pressing Alt+Tab). When I opt for Fullscreen or Custom, key combinations are not used by the x2go agent.

Ctrl + Alt + G shortcut has no effect at all.

Is it possible to switch keyboard combinations from the client to the remote desktop session?

I am using this windows client to access Ubuntu:

When I reconnect, clipboard usually works, but some time later it usually stop working. But clipboard I mean copying in windows and pasting in Windows. This is version of my server: 4.1.0.3-0~1708~ubuntu18.04.1. Are there any related known issues? I was not able to google anything, but this happens regularly and reproduces for other developers in my team.

When I try to server with x2goclient, I get this error:

how can I fix it?

UPDATE: Both computers are on same local network with no firewalls, ssh connection between them works perfectly. Both computers are running Ubuntu 18.04, software versions: x2goserver 4.1.0.0-3 and x2goclient 4.1.1.1-2.